Compounds for triplet-triplet annihilation upconversion

Abstract

Novel compounds, and in particular, a dendritic system for improved triple-triplet annihilation upconversion (TTA-UC) are provided. The core of the dendrimer compound includes a metal complex, and on the peripheral, multiple acceptor moieties are covalently linked to the core through a spacer. Consequently, a high efficiency TTA-UC system in both solution and solid state is provided, with particularly high efficiency in the solid state. Additionally, organic light emitting devices (OLEDs) comprising a layer including these novel compounds are provided.

The invention claimed is: 
     
       1. A compound for triplet-triplet annihilation upconversion comprising:
 a metal complex sensitizer core; 
 a first acceptor group; and 
 a first spacer group between the metal complex core and the first acceptor group, wherein the first acceptor group has a first triplet energy lower than a first triplet energy of the metal complex sensitizer core; 
 wherein the metal complex sensitizer core and the first acceptor group are jointly capable of performing triplet-triplet annihilation upconversion of light incident on the compound. 
 
     
     
       2. The compound of  claim 1 , wherein the first spacer group substantially surrounds the metal complex sensitizer core. 
     
     
       3. The compound of  claim 1 , further comprising a second spacer group, wherein the second spacer group substantially surrounds the first acceptor group. 
     
     
       4. The compound of  claim 3 , further comprising a second acceptor group. 
     
     
       5. The compound of  claim 4 , wherein the second acceptor group substantially surrounds the second spacer group. 
     
     
       6. The compound of  claim 1 , further comprising a second acceptor group. 
     
     
       7. The compound of  claim 1 , further comprising a second spacer group. 
     
     
       8. A device comprising a layer, the layer comprising a compound of  claim 1 . 
     
     
       9. The device of  claim 8 , wherein the device comprises an OLED. 
     
     
       10. The device of  claim 9 , further comprising a thin film encapsulation layer disposed over or under the OLED. 
     
     
       11. A consumer product comprising the compound of  claim 1 . 
     
     
       12. The compound of  claim 1 , wherein the first acceptor group is not bonded directly to the metal complex sensitizer core. 
     
     
       13. The compound of  claim 12 , wherein the first acceptor group is covalently linked to the metal complex sensitizer core through the first spacer group. 
     
     
       14. A compound for triplet-triplet annihilation upconversion, wherein the compound has the following general structure: 
       
         
           
           
               
               
           
         
         wherein A is a metal complex; 
         wherein L 1 to L x  is a spacer group; 
         wherein B 1  to B x  is an acceptor group B; 
         wherein m 1  is greater than 0; 
         wherein m x  is equal to or greater than 0, 
         wherein n is greater than 0, 
         wherein the acceptor group B has a first triplet energy lower than a first triplet energy of the metal complex A; and 
         wherein the metal complex A and the acceptor group B are jointly capable of performing triplet-triplet annihilation upconversion of light incident on the compound. 
       
     
     
       15. The compound of  claim 14 , wherein ml is in the range of 1 to 20. 
     
     
       16. The compound of  claim 14 , wherein mx is in the range of 0 to 20. 
     
     
       17. The compound of  claim 14 , wherein n is in the range of 1 to 20. 
     
     
       18. The compound of  claim 14 , wherein the metal complex is selected from the group consisting of: an iridium complex, an osmium complex, a platinum complex, a palladium complex, a rhenium complex, a ruthenium complex, and a gold complex. 
     
     
       19. The compound of  claim 14 , wherein the acceptor group B is a fused aromatic group. 
     
     
       20. The compound of  claim 14 , wherein the acceptor group B is selected from the group consisting of: naphthalene, anthracene, tetracene, pyrene, chrysene, and perylene. 
     
     
       21. The compound of  claim 14 , wherein the ratio of the acceptor group B to the metal complex A is at least 4. 
     
     
       22. The compound of  claim 14 , wherein the spacer group Lis selected from the group consisting of: alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, ester, and combinations thereof. 
     
     
       23. A device comprising a layer, the layer comprising a compound of  claim 14 . 
     
     
       24. The device of  claim 23 , wherein the device comprises a light emitting diode. 
     
     
       25. The device of  claim 23 , wherein the device comprises an OLED. 
     
     
       26. The device of  claim 25 , further comprising a thin film encapsulation layer disposed over or under the OLED. 
     
     
       27. A consumer product comprising the compound of  claim 14 . 
     
     
       28. A photovoltaic device comprising the compound of  claim 14 . 
     
     
       29. A device, comprising:
 an organic light emitting device comprising an emissive material having an emissive spectrum; and 
 an up-conversion layer disposed adjacent to the organic light emitting device such that light emitted by the organic light emitting device is incident on the up-conversion layer, the up conversion layer comprising the compound of  claim 14 . 
 
     
     
       30. A compound selected from the group consisting of: